MacNeill, 57, initially was expected to return to his jail cell sometime Friday, but doctors later reported he would be staying for at least an extra day or two of observation, Cannon said.
Inmates are issued disposable razors periodically for brief shaving use 15 minutes or so and then are required to return them, Cannon said. Jailers instead found MacNeill cutting himself with the blade.
MacNeill resisted the deputies' efforts to stop him, Cannon said.
"He was not happy the deputies had interrupted his attempt," Cannon said. "He was not completely cooperative."
When asked whether MacNeill tried to hurt the deputies, Cannon said, "I wouldn't say that."
On Nov. 9, following a four-week trial, MacNeill was convicted by a 4th District Court jury on charges of first-degree felony murder and second-degree felony obstruction of justice in the slaying of 50-year-old Michele MacNeill in April 2007.
Prosecutors claimed the physician had given his wife a cocktail of powerful drugs and then drowned her in a bathtub in order to carry on his affair with now-37-year-old Gypsy Willis the same woman he hired as a nanny for his children just two weeks after his wife died.
Already facing up to life in prison when sentenced on Jan. 7, MacNeill is also charged in a sex assault case stemming from allegations he put his hands down the pants of an adult female relative in 2007 and then asking her to sign a statement saying he did not touch her.
MacNeill's defense attorney, Randall Spencer, said Friday he did not know of the suicide attempt until he heard it on the morning news.
"The truth of the matter is that I had to find this out from the media," Spencer said. "The jail didn't bother to call me."
Spencer said that MacNeill had not seemed depressed during their visits recently. He said he is required to notify the jail if he has any indication MacNeill plans to kill himself.
"I haven't notified the jail recently, but I have done so in the past," Spencer said. "Obviously he is not happy, though, being convicted of something he didn't do."
Spencer's co-counsel, Susanne Gustin, said MacNeill had an attorney visit him earlier in the day Thursday.
"We're very sad and very concerned for him," Gustin said. "We had no idea that he was in this bad of shape. ... Otherwise we would have notified the jail and he would be on suicide watch."
Gustin said she and Spencer had been barred from visiting MacNeill in the hospital and may take the issue to a judge.
"We think we should be able to see him there," she said.
The defense attorneys had earlier said they were exploring an appeal for MacNeill.
When MacNeill returns to jail, he will be on suicide watch, Cannon said. He said that inmates on suicide watch generally are placed in a cell that can be viewed directly by a guard 24 hours a day, are not permitted unsupervised razor use and are placed in a special garment of strong material that cannot be torn and refashioned into a noose.